Black Box Explains...FDDI
Fiber Distributed Data Interface (FDDI) is a networking standard for operating at speeds of up to 100 Mbps. The standard FDDI network is set up in a ring topology with... more/see it nowtwo rings that transmit signals in opposite directions to a series of nodes. FDDI accommodates up to 500 nodes per dual-ring network with spacing up to 2 kilometers between adjacent nodes. FDDI uses the same token-passing scheme as the IEEE 802.5 Token Ring network to control transmission around the loop. collapse
Black Box Explains...Low-profile PCI serial adapters.
Ever notice that newer computers are getting smaller and slimmer? That means regular PCI boards wont fit into these computers low-profile PCI slots. But because miniaturization is the rage in... more/see it nowall matters of technology, it was only a short matter of time before low-profile PCI serial adapters became available—and Black Box has them.
Low-profile cards meet the PCI Special Interest Group (PCI-SIG) Low-Profile PCI specifications, the form-factor definitions for input/output expansion. Low-Profile PCI has two card lengths defined for 32-bit bus cards: MD1 and MD2. MD1 is the smaller of the two, with cards no larger than 4.721 inches long and 2.536 inches high. MD2 cards are a maximum of 6.6 inches long and 2.536 inches high.
BLACK BOX® Low-Profile Serial PCI cards comply with the MD1 low-profile specification and are compatible with the universal bus. Universal bus is a PCI card that can operate in either a 5-V or 3.3-V signaling level system. collapse
Mounting flat-screen displays.
Traditionally, computer monitors, TVs, or other video displays have simply been placed on a shelf or desktop. However, today’s flat screens are less stable than older vacuum-tube displays and should... more/see it nowbe secured to prevent tipping. Fortunately, most new displays meet the VESA standard, meaning they have a hole pattern on the back that fits any VESA standard mounting device such as a wall mount, desktop mount, or ceiling mount. This enables you to secure the display to prevent damage from accidental jolts and bumps. Additionally, a mounted display is less likely to be the object of theft. collapse
DisplayPort is a digital video interface that was designed by the Video Electronics Standards Association (VESA) in 2006 and has been produced since 2008. It’s incredibly versatile, with the capability... more/see it nowto deliver digital video, audio, bidirectional communications, and accessory power over a single connector.
DisplayPort cables are targeted at the computer world rather than at consumer electronics. DisplayPort is used to connect digital audio/video computers, displays, monitors, projectors, HDTVs, splitters, extenders, and other devices that support resolutions up to 4K and beyond. Unlike HDMI, however, DisplayPort is an open standard with no royalties.
With the proper adapters, DisplayPort cable can carry DVI and HDMI signals, although this doesn’t work the other way around—DVI and HDMI cable can’t carry DisplayPort. Because DisplayPort can provide power to attached devices, DisplayPort to HDMI or DVI adapters don’t need a separate power supply.
DisplayPort supports cable lengths of up to 15 meters with maximum resolutions at cable lengths up to 3 meters. Bidirectional signaling enables DisplayPort to both send and receive data from an attached device.
DisplayPort v1.1: 10.8 Gbps over a 2-meter cable.
DisplayPort v1.2: 21.6 Gbps (4K). DisplayPort v1.2 also enables you to daisychain up to four monitors with only a single output cable. It also offers the future promise of DisplayPort Hubs that would operate much like a USB hub.
DisplayPort v1.3: 2.4 Gbps. (5K)
The standard DisplayPort connector is very compact and features latches that don’t add to the connector’s size. Unlike HDMI, a DisplayPort connector is easily lockable with a pinch-down locking hood, so it can't be easily dislodged. However, a quick squeeze of the connector releases the latch.
The Mini DisplayPort (MiniDP or mDP) is a miniatured version of the DisplayPort interface. It carries both digital and analog computer video and audio signals. Apple® introduced the Mini DisplayPort connector in 2008 and it is now on all new Mac® computers. It is also being used in newer PC notebooks. This small form factor connector fully supports the VESA DisplayPort protocol. It is particularly useful on systems where space is at a premium, such as laptops, or to support multiple connectors on reduced height add-in cards.
Black Box Explains...Coax connectors.
The BNC (Bayonet-Neill-Concelman) connector is the most commonly used coax connector. This large ”bayonet“ connector features a slotted outer conductor and an inner plastic dielectric, and it offers easy connection... more/see it nowand disconnection. After insertion, the plug is turned, tightening the pins in the socket. It is widely used in video and Radio Frequency (RF) applications up to 2.4 GHz. It is also common in 10BASE2 Ethernet networks, on cable interconnections, network cards, and test equipment.
The TNC connector is a threaded version of the BNC connector. It works in frequencies up to 12 GHz. It‘s commonly used in cellular telephone RF/antenna applications.
The N connector is a larger, threaded connector that was designed in the 1940s for military systems operating at less than 5 GHz. In the 1960s, improvements raised performance to 12 GHz. The connector features an internal gasket and is hand tightened. It is common on 2.4-GHz antennas.
The UHF connector looks like a coarse-threaded, big center-conductor version of the N connector. It was developed in the 1930s. It is suitable for use up to 200–300 MHz and generally offers nonconstant impedance.
The F connector is most often used in cable and satellite TV and antenna applications; and it performs well at high frequencies. The connector has a 3/8–32 coupling thread. Some F connectors are also available in a screw-on style.
The SMA (Subminiature A) connector is one of the most common RF/microwave connectors. This small, threaded connector is used on small cables that won’t be connected and disconnected often. It’s designed for use to 12.4 GHz, but works well at 18, and sometimes even up to 24 GHz. This connector is often used in avionics, radar, and microwave communications.
The SMC (Subminiature C) connector is a small, screw-on version of the SMA. It uses a 10–32 threaded interface and can be used in frequencies up to 10 GHz. This connector is used primarily in microwave environments.
The SMB (Subminiature B) connector is a small version of the SMC connector. It was developed in the 1960s and features a snap-on coupling for fast connections. It features a self-centering outer spring and overlapping dielectric. It is rated from 2–4 GHZ, but can possibly work up to 10 GHz.
The MCX (Micro Coax) connector is a coax RF connector developed in the 1980s. It has a snap-on interface and uses the same inner contact and insulator as the SMB connector but is 30% smaller. It can be used in broadband applications up to 6 GHz.
The ANSI/ISA Standard and Hazardous Locations
Fires and explosions are a major safety concern in industrial plants. Electrical equipment that must be installed in these locations should be specifically designed and tested to operate under extreme... more/see it nowconditions. The hazardous location classification system was designed to promote the safe use of electrical equipment in those areas “where fire or explosion hazards may exist due to flammable gases or vapors, flammable liquids, combustible dust, or ignitable fibers of flyings.”
The NEC and CSA define hazardous locations by three classes:
Class 1: Gas or vapor hazards
Class 2: Dust hazards
Class 3: Fibers and flyings
Division 1: An environment where ignitable gases, liquids, vapors or dusts can exist
Division 2: Locations where ignitables are not likely to exist
Hazardous classes are further defined by groups A, B, C, D, E, F, and G:
C. Ethlene, carbon monoxide
D. Hydrocarbons, fuels, solvents
F. Carbonaceous dusts including coal, carbon black, coke
G. Flour, starch, grain, combustible plastic or chemical dust
Our line of Industrial Ethernet Switches (LEH1208A, LEH1208A-2GMMSC, LEH1216A and LEH1216A-2GMMSC) is fully compliant with ANSI/ISA 12.12.01, a construction standard for Nonincendive Electrical Equipment for Use in Class I and II, Division 2 and Class III, Divisions 1 and 2 Hazardous (Classified) Locations. ANSI/ISA 12.12.01-2000 is similar to UL1604, but is more stringent (for a full list of changes, see Compliance Today). UL1604 was withdrawn in 2012 and replaced with ISA 12.12.01.
The standard provides the requirements for the design, construction, and marking of electrical equipment or parts of such equipment used in Class I and Class II, Division 2 and Class III, Divisions 1 and 2 hazardous (classified) locations. This type of equipment, in normal operation, is not capable of causing ignition.
The standard establishes uniformity in test methods for determining the suitability of equipment as related to their potential to ignite to a specific flammable gas or vapor-in-air mixture, combustible dust, easily ignitable fibers, or flyings under the following ambient conditions:
a) an ambient temperature of -25°C to 40°C.
b) an oxygen concentration of not greater than 21 percent by volume.
c) a pressure of 80 kPa (0.8 bar) to 110 kPa (1.1 bar).
The standard is available for purchase at www.webstore.ansi.org. To learn more about ANSI/ISA 12.12.01 and hazardous location types, visit https://www.osha.gov/doc/outreachtraining/htmlfiles/hazloc.html.
Black Box Explains...Fiber optic ferrule sleeves.
In a fiber optic adapter, the internal ferrule sleeve holds the fiber in place and aligns the filament of one fiber ferrule with its mate. The ferrule sleeve is the... more/see it nowmost expensive component to manufacture in a fiber optic adapter, accounting for approximately 80% of the total adapter cost.
The ferrule alignment sleeves are also the most critical part of a fiber optic connection process. They provide the bridge between one cables ferrule and another cables ferrule interface. The precision of the ferrule sleeve and its hole determines how well the fibers align, which affects the light signal transmission.
Fiber optic adapters are generally made with ceramic or metal ferrule sleeves. Some adapters also feature ferrule sleeves that are a combination of these materials.
Ceramic ferrule sleeves are more precisely molded and fit close to the fiber ferrule. This precise molding gives the fiber optic connection a lower optical loss. As a general rule, use ceramic ferrule sleeves for critical network connections, such as backbone runs in highly secure networks or for connections that will be changed frequently, like those in wiring closets. Ceramic ferrule sleeves best suit single-mode cable connections.
Ferrule sleeves made of metal, such as bronze ferrules, offer more durability than ceramic sleeves, but they may not offer the same precision alignment as ceramic ferrule sleeves. Drilling an accurate hole through the metal ferrule sleeve can be difficult, and that can result in less accurate fiber alignment. The use of watch-jeweled centering improves alignment. But overall, metal ferrule sleeves are better suited for multimode fiber applications where absolute alignment isnt crucial.
Black Box Explains...Upgrading from VGA to DVI video.
Many new PCs no longer have traditional Cathode Ray Tube (CRT) computer monitors with a VGA interface. The latest high-end computers have Digital Flat Panels (DFPs) with a Digital Visual... more/see it nowInterface (DVI). Although most computers still have traditional monitors, the newer DFPs are coming on strong because flat-panel displays are not only slimmer and more attractive on the desktop, but they’re also capable of providing a much sharper, clearer image than a traditional CRT monitor.
The VGA interface was developed to support traditional CRT monitors. The DVI interface, on the other hand, is designed specifically for digital displays and supports the high resolution, the sharper image detail, and the brighter and truer colors achieved with DFPs.
Most flat-panel displays can be connected to a VGA interface, even though using this interface results in inferior video quality. VGA simply cant support the image quality offered by a high-end digital monitor. Sadly, because a VGA connection is possible, many computer users connect their DFPs to VGA and never experience the stunning clarity their flat-panel monitors can provide.
It’s important to remember that for your new DFP display to work at its best, it must be connected to a DVI video interface. You should upgrade the video card in your PC when you buy your new video monitor. Your KVM switches should also support DVI if you plan to use them with DFPs. collapse
Black Box Explains: M1 connectors.
In 2001, the Video Electronics Standards Association (VESA) approved the M1 Display Interface System for digital displays. The M1 system is a versatile and convenient system designed for computer displays,... more/see it nowspecifically digital projectors. M1 supports both analog and digital signals.
M1 is basically a modified DVI connector that can support DVI, VGA, USB and IEEE-1394 signals. The single connector replaces multiple connectors on projectors. An M1 cable can also be used to power accessories, such as interface cards for PDAs.
There are three primary types of M1 connectors:
–M1-DA (digital and analog). This is the most common connector, and it supports VGA, USB and DVI signals.
–M1-D (digital) supports DVI signals.
–M1-A (analog) supports VGA signals.
The M1 standard does not cover any signal specifications or detailed connector specifications. collapse